<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    /*（5）双飞翼布局，双飞翼布局相对于圣杯布局来说，左右位置的保留是通过中间列的 margin 值来实现的，而不是通过父元
    素的 padding 来实现的。本质上来说，也是通过浮动和外边距负值来实现的。*/
    .outer {
      height: 100px;
      background-color: pink;
    }

    .left {
      /* position: relative;
      left: -100px; */
      float: left;
      width: 100px;
      height: 100px;
      margin-left: -100%;
      background-color: tomato;
    }

    .right {
      /* position: relative;
      left: 200px; */
      float: left;
      width: 200px;
      height: 100px;
      margin-left: -200px;
      background-color: gold;
    }
    .wrapper {
      float: left;
      width: 100%;
      height: 100px;
      background-color: lightgreen;
    }
    .middle {
      margin-left:100px;
      margin-right:200px;
      height: 100px;
    }
  </style>
</head>

<body>
  <div class="outer ">
    <div class="wrapper">
      <div class="middle">middle</div>
    </div>
    <div class="left">left</div>
    <div class="right">right</div>
  </div>
</body>

</html>